Sewing machine mechanism



April' 27, 1943. STQTZ 2,317,698

SEWING MACHINE MECHANISM Filed Aug. 16, 1940 INVENTOR. Owzuzs A? 57072.

T'atented Apr. 27, 1943 umrso STATES PATENT OFFICE SEWING MAOHINE MECHANISM Charles K. Stotz, Farmington, C'onn., assignor to The Cha-Gobe Company, Hartford, Conn., a corporation of Connecticut Application August 16, 1940, Serial No. 352,924

4. Claims.

This invention relates to a sewing machine mechanism that is particularly adapted for such machines as are used to sew along the edge of a piece of material and the primary object of the invention is to provide a mechanism which can be attached to sewing machines of the overedge stitch type so as to retain a piece of work in position for an operation thereon by said machine.

A further object of the invention is to provide a mechanism which is particularly adapted to retain a disc of material on a sewing machine while an over-edge stitch is being applied along the edge of the disc.

A further object is to provide a mechanism which will hold a disc in position and rotate the same under the needle of the machine while an over-edge stitch is applied to the edg of the disc and an elastic member is secured to said edge by the stitch.

Further objects of the invention will be clearly understood from the following description and the accompanying drawing in which:

Fig. 1 is a plan view of a mechanism embodying my invention.

Fig. 2 is a side view thereof.

Fig. 3 is a front view.

Fig. 4 is a bottom view with certain parts omitted therefrom.

Fig. 5 is a fragmentary plan view on an enlarged scale illustrating the operation of my invention.

Fig. 6 is a view in central vertical portion on line 6-6 of Fig. 5.

Fig. 7 is a plan view showing an article which is made in the operation of the mechanism embodying my invention.

Fig. 8 is a front view in vertical section on line 8-8 of Fig. 1.

As illustrated in the drawing, my improved mechanism comprises a table plate 5 whichis adapted to be secured to a conventional form of sewing machine by means of a screw 6.

The sewing machine may comprise a carrying member I having an oscillating member 8 which is common in well known makes of sewing machines and which may be operated by a rotatable shaft 9 having a crank l therein operating a crank block H in a slot l2 for reciprocating the said member 8 in a vertical direction.

A train of gears comprising a driving gear l3, an intermediate gear l4 and a driven gear I is mounted within a recess H5 in the plate 5 by means of shafts extending into said plate. A ratchet wheel l! is secured to the shaft l8 on the driving wheel l3 and disposed on the underside of the plate 5. The said ratchet is operated by means of a pawl bar I9 which is slidable in a supporting strap 20 and held in engagement with the ratchet I! by means of a spring |9a and operated against the ratchet by means of a lever 2| which is actuated by a bar 22 that is slidabl mounted to the said plate 5 as at 23. V

An operating cam 24 is adjustably secured to the oscillating member 8 by means of a screw 25 in operative engagement with the bar 22.

A work carrier, in the form of a disc 26, is mounted upon the shaft 21 to be rotated by the gear l5, and a notch 28 is provided in the plate 5 adjacent to the said work carrier in order to receive the needle 29 of the sewing machine which is ordinarily timed with the member '8. This needle may be of any conventional form such as used in over-edge stitching machines and, may havein connection therewith, a looper, not shown, which carries the thread over the edge of the work.

A material clamping member 30 having a recess 3| in the bottom thereof and a knob 32 is provided for clamping a disc of material 33 in engagement with the work carrier 26 as clea'rly'illustrated in Fig. 6 of the drawing. The said clamping member is provided with slits 34 to render the same resilient so as to apply yielding tension against the disc on the work carrier 26 and thereby securely clamp the said disc to the carrier.

The operation of the above described mechanism is as follows:

A disc of material, such as cloth or the like, is first clamped upon thework carrier by placing the same concentrically therein and forcing the clamping member 30 downwardly thereover.

The sewing machine is then started in operating motion and reciprocation of the cam 24 will.

oscillate the operating bar 22 which will rock the lever 2| and thereby operate the pawl I9 against the ratchet wheel ll; the spring |9a tending to urge the said pawl against the ratchet wheel while also applying backward tension to the said pawl and, therefrom and through the lever 2|, resiliently forcing the operating bar 22 towards the surface of the cam 24; the end of the slot 23-a acting against the screw 23 to serve as a stop for spacing the bar from the cam so that, by adjusting the cam 24, different numbers of teeth on the ratchet Il may be jumped for regulating the rate of rotation of the work holder 26.

Rotation of the ratchet wheel M, will, through the shaft l8, rotate the gear l3 and, through the 4 disc.

intermediate gear l4, rotate the work carrier 26 which in turn will rotate the disc of material 33 in the direction indicated by the arrow in Fig. and thereby moving the peripheral edge portion of said disc under the needle 29 while the overedge stitch, indicated at 36, is applied to said In the particular form of work shown in the drawing, said over-edge stitch may be used for binding an elastic member 3! to the edge of the disc. The said elastic member may be stretched while it is being sewn to said edge so that, when the sewing operation is completed and the disc detached from the work carrier, the said elastic member will draw the peripheral portions of the disc inwardly into a pouch form to provide an article as illustrated in Fig. '7 that is particularly adapted for use as a nasal filter or the like. This invention is of particular advantage in producing nasal filters, as shown, for the reason that they are so small in size that it would be very diflicult to perform the above described sewing operation thereon While holding the work by hand.

Furthermore, it has been common practice to apply the over-edge stitch to discs of material by periphery of the disc, in order that a new grip may be obtained on the disc. My invention renders it possible to apply the stitching around the entire periphery of a disc with a single continuous operation of a sewing machine thereby eliminating the frequent stopping and starting thereof and reducing the time required for the stitching operation on each disc. My invention also eliminates the necessity of the conventional form of work feeder mechanism in a sewing machine which is usually designed to feed the work in a straight line and which is therefore not fully satisfactory for moving work in a circular path.

It is desired to have it understood that while I have shown and described the application of an over-edge stitch to the peripheral portion of a disc shaped piece of material, my invention is also adapted for use with other forms of stitches.

I claim:

1. For a sewing machine of the character described comprising means including a needle for operating said lever, an adjustable cam carried by said machine for actuating said bar, and a single spring urging said pawl into engagement with said ratchet and said bar in the direction of said cam.

2. In a sewing machine of the character described comprising means including a needle for applying over-edge stitching along the edge of a piece of material, a vertically oscillating member, mechanism including a work carrier member rotatable on an axis spaced from said needle, a ratchet movable with said work carrier, a pawl engageable with said ratchet, a lever for operating said pawl, a slidable bar for operating said lever, stop means for limiting the movement of said bar in one direction, a single spring urging said pawl into engagement with said ratchet nd said bar against said stop means, a cam bar 0 rried by said oscillating member for moving said slidable bar in a direction away from said stbp means to cause rotation of said ratchet; said cam bar providing lost motion between it and said slidable bar, and means for adjusting said cam bar on said oscillating member to vary said lost motion for varying the speed of rotation of said work carrier.

3. A sewing machine of the character described comprising a mechanism which includes a table, a work carrier rotatably mounted on the top of said table, a gear train for rotating said work carrier; said gear train being rotated in a recess in the top of said table and on a plane below the plane of said work carrier, a rachet mechanism under said table for rotating said gear train, said rachet mechanism including a slidable bar having a portion thereof extending free of said table, a vertically oscillating member in said machine, anda cam-shaped bar depending from said member in position to engage said extending portion of the slidable bar for operating the rachet mechanism.

4. A sewing machine of the character described comprising a needle, a work carrier and a rachet mechanism for rotating said work carrier with relation to said needle; said rachet mechanism including a rachet wheel, a pawl in engagement with said rachet wheel, a lever for actuating said pawl, a slide bar for actuating said lever, cam means for operating said bar and a spring connected to said pawl; said spring being disposed at an angle to the axis of said pawl for urging said pawl into engagement with .said rachet wheel and through said pawl also urging the said slidable bar in the direction of the cam means.

CHARLES K. STOTZ. 

